Electrostatic flocking apparatus



United States Patent [72] Inventor Samuel M. Schwartz Paterson, New Jersey (404 Cliflon Ave., Clifton, NJ. 07015) [21 Appl. No. 742,944

[22] Filed July 5, 1968 [45] Patented Sept. 29, 1970 [54] ELECTROSTATIC FLOCKING APPARATUS 3 Claims, 3 Drawing Figs.

[52] 11.8. CI....L 118/624, 118/636,118/638,1l8/640 [51] Int. Cl B05b 5/00 [50] Field olSearcln; 1 18/624, 627, 636, 638, 630, 634, 208, 309, 312; 117/17, 17.5

[56] References Cited UNITED STATES PATENTS 2,715,585 8/1955 Schwartz et al 118/638X 2,976,839 3/1961 Okma et al. 118/624 3,255,730 6/1966. Gl'ohl 118/624 3,269,356 3/1966 Fridel'ici 118/640 3,375,124 3/1968 Linneborn... 117/17 3,379,175 4/1968 Spencer 117/17X 3,426,730 2/1969 Lawson et al 1 18/640)( Primary Examiner-Morris Kaplan Attorney-Harry Price ABSTRACT: Electrostatic flocking apparatus including means feeding a substrate through the space between a pair of vertically aligned electrodes. Means reciprocate the upper electrode in its own plane and means operate to simultaneously vibrate the upper electrode in a vertical direction. A

flock feeding device is located above the upper electrode. The flock is desirably of any composition other than metallic, such as finely chopped or otherwise divided fibres or particles of materials, including vegetable or animal matter, or nylon or other cellulosic or nitrogeneous fibres of natural or synthetic origin other than metallic substances may be used.

Patented Sept. 29, 1970 Sheet Patented Sept. 29, 1970 INVENTOR. 5447051 M smn M/"z ELECTROSTATIC F LOCKING APPARATUS DESCRIPTION OF THE INVENTION The present invention relates to flocking apparatus, and in particular to electrostatic flocking whereby the flock is charged electrostatically so as to be properly oriented when deposited upon the material to which the flock adheres according to a predetermined pattern.

The sheet material which is to be treated, which may be paper, a textile fabric or a plastic sheet material or the like, may be flexible, semirigid or rigid, and it may be provided on one face with an overall coating or predetermined pattern of adhesive. Thisface is to receive the flock, which flock may be in the form of finely chopped or otherwise divided fibres or particles of materials, including vegetable or animal matter, nylon or other synthetic or nitrogenous fibres of natural or synthetic origin other than metallic substance.

The general type of flocking apparatus to which the present invention relates is disclosed in U.S. Pat. No. 2,715,585. As is indicated in the latter patent, great advantages are to be achieved from utilizing a ,suitably apertured reciprocating upper electrode to which, together with a lower electrode, an alternating potential of high voltage is applied so that the flock element, which behaves in a unique manner different from any particular material, will be properly oriented with respect to each other when deposited upon the material which is to be flocked.

Although it has been found that the procedures and apparatus disclosed in U.S. Pat. No. 2,715,585 achieve the desired results in a highly satisfactory manner, nevertheless it has been found that there is a tendency for the flock to accumulate to an undesirable. extent on the reciprocating upper electrode. This electrode is purposely constructed, as shown in the above patent, in such a way that its components are tapered so as to diverge downwardly in cross section, and while this construction will to some extent oppose any tendency of the flock to accumulate undesirably on the upper electrode, it is a primary object of the present invention to. provide an apparatus which will to an even greater extent prevent undesirable accumulation of flock on the upper electrode.

In particular, it is an object of the invention to achieve this prevention of flock accumulation on the upper electrode without substantially changing the basic structure of the upper electrode so that the outstanding advantages which are achieved with the procedures and apparatus of the above patent will be retained.

Thus, it is an object of the invention to provide a machine which will in no way interfere with the normal operation of a flocking machine.

Furthermore, it is an object of the invention to provide a structure which can readily be incorporated into existing flocking machines without requiring any substantial reconstruction thereof.

Furthermore, it is an object of the invention to provide a structure which can achieve the above objects while at the same time being exceedingly simple and inexpensive as well as reliable in operation.

Furthermore, it is an object of the invention to provide a simple rugged structure in which none of the components conflict with the operation of other components or in any way oppose the desired operation thereof.

In particular the apparatus of the invention includes the step of and apparatus for vibrating the upper electrode so that through these vibrations which are imparted to the electrode, in accordance with the present invention, the tendency of flock to accumulate thereon will be reduced to an extent even greater than that achieved with the structure of U.S. Pat. No. 2,715,585.

Because of the vibrations which are imparted to the upper electrode in accordance with the present invention a particular problem is encountered in supporting this upper electrode for reciprocating movement, andit is an object of the invention also to provide a highly satisfactory solution to this latter problem.

BRIEF DESCRIPTION OF DRAWINGS The invention is illustrated by way of example in the accompanying drawings which form part of the application and in which:

FIG. 1 is a partly schematic sectional elevation of one possible apparatus, according to the present invention, the section of FIG. 1 being taken in a plane which extends in the direction of movement of the material onto which the flock is applied.

FIG. 2 is a transverse section of part of the structure of FIG. 1, taken along line 2-2 of FIG. I in the direction of the arrows.

FIG. 3 is a top plan view of the structure of FIG. 2 taken along line 3-3 of FIG. 2 in the direction of the arrows.

Referring now to the drawings, the structure includes a container 10, the interior of which may have its temperature and humidity controlled in a well-known manner. This container 10 is carried by a suitable framework 12 whose legs 14 rest on the floor 16, as indicated in FIG. 1. The walls of the container 10 are only schematically indicated in FIG. 1 and some of them are omitted from FIG. 2 for the sake of clarity.

The front wall 18, which is not visible in FIG. 1, is provided with a safety window 20 through which the interior of the container 10 can be inspected. The outline of the window 20 is indicated in dotted lines in FIG. 1.

The flock which is to be deposited on the moving sheet material is delivered in any known way into the interior of a hopper 22 carried by the top wall of the container 10. This top wall is formed with an opening giving access to the interior of the hopper 22. Within the hopper 22 is situated a rotary brush 24 as well as a rotary assembly 26 used to stir up the flock and prevent it from agglomerating. This rotary assembly 26 includes a pair of end discs between which rods 28 extend, these rods turning so as to keep the flock in motion and guarantee that it reaches the brush 24 in loose condition. The brush 24 is driven by a belt drive from a motor 30 carried by the framework 12, and an additional belt drive transmits the drive to the rotary stirring assembly 26.

The flock 32 discharges downwardly from the bottom open end of the hopper 22 in the manner indicated schematically in FIG. 1. The bristles of the rotary brush 24 press against the opposed inner side surfaces of the hopper 22 and the ends of the brush 24 are located closely adjacent to the end walls of the hopper, so that flock is delivered only during rotation of the brush 24. In addition there is in the interior of the hopper 22 a projecting member 34 which engages the bristles to cause them to snap so as to promote the best possible delivery of the flock from the hopper.

Situated directly beneath the hopper is a sieve 36 which is oscillated by a rotary eccentric assembly 38 driven in any suitable way, and the end of the sieve 36 distant from the eccentric assembly 38 is freely suspended by a flexible member 40 carried by a bracket 42 connected to the underside of the top wall of the container 10.

This construction is substantially identical with that of U.S. Pat. No. 2,715,585, and the assembly may include a structure as shown in the latter patent for conveying away excess flock which is delivered to the sieve 36.

Situated just beneath the sieve 36 is the upper electrode 44 in the form of a metal plate having intersecting bar portions arranged according to the pattern shown in FIG. 3, so that in this way the upper electrode 44 is formed with a plurality of apertures or openings 46 through which the flock must pass before reaching the space between this upper electrode 44 and a lower stationary electrode 46.

The lower stationary electrode 46 is carried by suitable insulating support assemblies 48 which are in turn supported by a bracket assembly 50 of the framework which supports the entire structure. The insulating assemblies 48 are directly connected with a supporting plate 52 to which the lower electrode 46 is bolted, and this electrode may have a rear ribbed surface engaging the supporting plate 52.The lower electrode 46 may have the structure of the lower electrode of the above U.S.

patent.

The framework of the machine includes additional supporting assemblies 54 which mount a glass plate 56 over and in engagement with the lower electrode 46, and it is along this glass plate that an endless blanket 58 moves The blanket or conveyor 58 is guided over the pulleys 60 in the manner shown schematically in FIG. 1, and these pulleys are supported in any suitable bearings. One of the pulleys is driven from any suitable source so as to constantly move the conveyor 58 during operation of the machine, and it is moved with its lower run advancing toward the left, as indicated by the arrow 62 in FIG. 1, so that the upper run moves along the glass plate from left to right, as viewed in FIG. 1.

The sheet material which is to receive the flock takes the form of a flexible sheet 64 made of any sheet material to which a pattern of adhesive has previously been applied. The adhesive pattern is situated on the upper face of the sheet 64. The walls of the container are suitably slotted so as to provide for unobstructed movement of the upper run of the blanket 58 together with the sheet material 64 through the machine in the manner indicated in FIG. 1. Additional rollers 66 are capable of being adjusted with the assemblies 68, schematically indicated in FIG. 1, so that in this way the tension in the blanket 58 can be regulated.

In a manner which may be the same as that disclosed in US. Pat. No. 2,715,585, a source of electricity may be operatively connected with the upper electrode 34 and the lower electrode 46 as so to apply to these electrodes a potential which will create in the space between the electrodes an elecrostatic charge which will properly orient the flock 32 in the manner set forth in the latter patent.

Simultaneously with the falling of the flock 32 through the openings of the upper electrode into the space between the latter and the lower electrode, so as to reach the upper surface of the sheet 64 which continuously advances through the machine, the electrode 44 is reciprocated in a direction transverse to the direction of movement of the sheet material 64. For this purpose the electrode 44 fixedly carries a bracket 70 having a pair of eyes 72 (FIGS. 2 and 3) which serve to carry a pin 74 on which one end ofa pitman 76 is pivoted. The pitman 76 extends through the aligned openings 78 of a pair of walls 80 of the machine, and the left wall 80 of FIG. 2 serves to support various bearings and motion-transmitting elements through which the shaft 82 is rotated. This shaft fixedly carries the eccentric 84 which rides in a ring 86 fixed with the outer end of the pitman 76 so that in this way the electrode 44 is reciprocated back and forth, as indicated by the arrows 88 in I FIG. 2.

In accordance with the present invention, simultaneously with its reciprocation, the upper electrode 44 is vibrated. The vibrations are provided by connecting a vibrating means 90 with the electrode 44. This vibrating means 90 may be a vibrator which in and of itself is of a known construction. Thus, it includes an outer frame or housing 92 which is bolted directly to the upper face of the electrode 44 at a location spaced from the central region of the electrode, as apparent from FIGS. 1 and 3. At its upper end the frame 92 carries electrical connecting structures through which unillustrated electrical leads can be connected to vibrator 90, and through these electrical connections the vibrator is energized so as to operate. Essentially the vibrator includes, as is well known, an electric motor on whose drive shaft is mounts-1. a pair of eccentrics which can be adjusted relative to each other so as to provide a predetermined unbalance during each revolution of the shaft of the motor and in this way the components of force derived from the vibrations of the vibrator 90 can be regulated. In the particular example shown in FIG. 2 the vibrations can tend to urge the upper electrode horizontally in the manner shown by the arrows 94 and vertically in the manner shown by the arrows 96, and these vibratory movements will be superimposed on the reciprocating movement derived from the rotary ec centric drive 84.

Of course, it IS important that the structure which guides the upper electrode for movement does not retard the vibratory forces which are imparted to the upper electrode 44, and for this reason the structure of the invention includes a special mounting structure which mounts the upper electrode for movement. This mounting structure includes a pair of elongated guide rails 98 fixed to the electrode 44 along opposed side edges thereof. At these side edges the electrode fixedly carries the elongated angle bars 100 whose hollow interiors are directed downwardly so as to receive the guide rails 98. These guide rails may be fixed to the upper electrode as by being welded thereto, and they ride on the grooved rollers 102 supported in suitable bearings carried by brackets 104 which are in turn fixed directly to the supporting framework 12. As is shown most clearly in FIG. 1, the grooves of the guide rollers 102 match the cross section of the rails 98 so that they ride smoothly on the grooved rollers 102. It is particularly to be noted that while the rails 98 have upper and lower surfaces, they are supported exclusively at their lower surfaces so that in this way unhindered vibrations can be transmitted to the electrode 44 from the vibrating means 90.

As a result of the above described structure of theinvention, it is possible to avoid any undesired accumulation of flock on the upper electrode.

The upper electrode in addition to having the construction already disclosed in the US. Pat. No. 2,l75,585, by being vibrated with the vibrating means of the invention will cause all flock to slide off any exposed surfaces of the upper electrode which may be engaged by the flock, and as a result all of the flock is very efficiently delivered to the lower region where the material 64 is situated. As a result of the addition of the vibrating means 90 to the assembly the possibility of any lack of uniformity in the deposition of the flock is avoided.

I claim:

1. A flock printing machine comprising:

a pair of upper and lower substantially horizontally arranged grid-type electrodes which are vertically aligned and spaced and adapted to receive a high alternating voltage imposed therebetween;

said upper electrode including a pair of guide rails fixed to opposite side portions thereof;

means to support said upper electrode comprising roll means complementarily shaped with respect to said guide rails;

means to reciprocate said upper electrode in its horizontal plane whereby to translate said rails across the supporting rolls;

means to vibrate said upper electrode in a vertical direction and simultaneously with the operation of said means to reciprocate whereby to effect an orbital vibratory path of movement of said upper electrode;

means to feed a substrate, to be flocked, in a horizontal path to and through the space defined by said electrodes; and

means vertically disposed above the upper electrode and adapted to feed flocking material to and through said upper electrode whereby the flock is subjected to the electrostatic field established between the electrodes and an aligned dispositon of said flock upon the substrate is effected.

2. The machine of claim 1 and wherein said upper electrode is fixed at opposed edges thereof with a pair of elongated angle bars extending along said opposed edges, fixed to said rails and having downwardly directed hollow interiors which respectively receive said rails.

3. The machine of claim 2 and wherein said rails are of circular cross section and have free ends projecting beyond said angle bars and said rolls comprise grooved rollers situated beneath and receiving said rails while the latter are free to vibrate with respect to said rollers. 

